Saudi Prince Alwaleed bin Talal has called on the Saudi Telecommunication Authority to drop reported plans to block social media platforms, describing the action -- if implemented -- as a "losing war."

The prince's words appear to refer to proposals thought to be under consideration by Saudi officials for tighter controls on social media, including steps that would mean Twitter users could be identified.

"Dear Saudi Telecommunication Authority, social media is a tool for the people to make the government hear their voices. Just thinking of blocking them is a losing war, and a way to put more pressure on the citizens," the prince wrote on his Twitter account Monday.

A number of Twitter users commented on this post. "They won't succeed in blocking our voices, Twitter is our world through which we'll send our voices," one wrote.

Rights groups have criticized Saudi Arabia, a conservative kingdom, for its efforts to stifle online dissent.

Freedom House, a U.S.-based free speech advocacy group, highlighted the limits imposed on free expression by Saudi Arabia in its report last year on Internet freedoms around the world, "Freedom on the Net 2012."

The kingdom was one of a number of countries in which "authorities imposed further restrictions following the political uprisings in Egypt and Tunisia, in which social media played a key role," it said.

Sanja Kelly, project director of Freedom on the Net, told CNN there had been an increasing number of arrests of Saudi Internet users who've posted critical remarks online, including on Twitter, since the report came out last September.

According to tracking by Freedom House, 51% of Saudi Internet users are active on Twitter, which is one of the highest ratios in the world.

"The Saudi authorities have been struggling for the past several years with decisions on how to deal with the growing and increasingly critical discussions online," Kelly said.

"In recent months there have been increasing proposals by the authorities to either limit access to social media or to increase surveillance and decrease privacy for users."

One proposal under discussion has been the introduction of a rule requiring each Saudi Twitter user to register using government ID, she said. It has not been implemented but has attracted a lot of attention because of the popularity of Twitter in the kingdom.

"If this really comes into reality, it would be in effect a way for the government to track who's posting what," she said.

Those at the liberal end of the spectrum in Saudi Arabia are outraged by the idea of such registration, she said. "They feel that at the moment one of the few ways for them to vent and to engage in political conversations is through social media," she said.

But at the other end of the spectrum, "there are a lot of conservative voices in Saudi Arabia who are saying that social media -- Twitter in particular -- is a huge waste of time," and so would support this kind of measure, Kelly said.

This division reflects a broader cleavage in Saudi society between progressives who are trying to push the boundaries of what is allowed and more conservative elements who are trying to maintain the status quo and see social media as a threat, she added.

Up to now, Saudi authorities have been able to identify more prominent social media users, but a change in the rules might mean those who post online under the cover of anonymity are also exposed, she said. A likely consequence would be increased self-censorship.

Bin Talal, who is one of many Saudi princes, is more prominent in business circles, Kelly added, so his more progressive views do not necessarily represent what is being discussed among the ruling elite.